Add a function to grab all pixel groups of size w x h
Define corner? predicate and transform function for map structure
Put all corner patterns in one map
Re-threshold after scaling
Add seesaw dependency back in (fixup to before seesaw usage)
Put filter-ops list at bottom of file
Define function for getting all RGB values
Make an accessor function creator

Takes an image, scales the x and y by the image width
Make a function for getting pixels by quads
Add a function for getting all corners
Make quads into an rectangle windowing function
Add three by three corner patterns